In general, a small-sized camera module is mounted in mobile terminals, such as smartphones. A lens driving device having an autofocus function of automatically performing focusing during capturing of a subject (hereinafter referred to as “AF (Auto Focus) function”) and a shake-correcting function (hereinafter referred to as “OIS (Optical Image Stabilization) function”) for reducing irregularities of an image by correcting shake (vibration) caused during capturing of an image is applied in such a camera module (see e.g. Patent Literatures (hereinafter referred to as “PTLs”) 1 and 2).
The lens driving device including the autofocus and shake-correcting functions is provided with an auto-focusing driving part for moving a lens part in the optical-axis direction (hereinafter, the auto-focusing driving part is referred to as “AF driving part”) and a shake-correcting driving part for swaying the lens part in a plane orthogonal to the optical-axis direction (hereinafter, the shake-correcting driving part is referred to as “OIS driving part”). In PTLs 1 and 2, a voice coil motor (VCM) is employed in the AF driving part and the OIS driving part.
The AF driving part of a VCM-driven system includes, for example, an auto-focusing coil part (hereinafter referred to as “AF coil part”) disposed at the periphery of the lens part, and an auto-focusing magnet part (hereinafter referred to as “AF magnet part”) disposed to be radially spaced apart from the AF coil part. An autofocus movable part (hereinafter referred to as “AF movable part”) including the lens part and the AF coil part is supported by an auto-focusing supporting part (hereinafter referred to as “AF supporting part” (e.g. plate spring)) such that the AF movable part is radially spaced apart from an autofocus fixing part (hereinafter referred to as “AF fixing part”) including the AF magnet part. Focusing is automatically carried out by moving the AF movable part in the optical-axis direction by utilizing a driving force of the voice coil motor composed of the AF coil part and the AF magnet part.
The OIS driving part of the VCM-driven system includes, for example, a shake-correcting magnet part (hereinafter referred to as “OIS magnet part”) disposed in the AF driving part and a shake-correcting coil part (hereinafter referred to as “OIS coil part”) disposed to be spaced apart from the OIS magnet part in the optical-axis direction. A shake-correcting movable part (hereinafter referred to as “OIS movable part”) including the AF driving part and the OIS magnet part is supported by shake-correcting supporting parts (hereinafter referred to as “OIS supporting parts” (e.g. suspension wires)) such that the shake-correcting movable part is spaced apart in the optical-axis direction from a shake-correcting fixing part (hereinafter referred to as “OIS fixing part”) including the OIS coil part. Shake correction is performed by swaying the OIS movable part with respect to the OIS fixing part in the plane orthogonal to the optical-axis direction by utilizing the driving force of the voice coil motor composed of the OIS magnet part and the OIS coil part.